What is this calculator for?
You graduated three years ago with $48,000 in federal student loans. You've been on the standard 10-year plan paying $530/month and it's eating your budget. You're trying to decide between income-driven repayment (smaller monthly, longer payoff), refinancing (lower rate via private lender, lose federal protections), or accelerating payoff (extra principal, finish earlier). The student loan calculator runs each scenario so you can compare honestly.
US student loans break into two types: federal (about 92% of student debt) and private (~8%). Federal loans have fixed interest rates set annually by Congress (2024-25 undergraduate Direct Subsidized/Unsubsidized: 6.53%; grad PLUS: 8.08%); flexible repayment plans (standard, graduated, extended, income-driven); federal protections (deferment, forbearance, forgiveness programs); and discharge in death/disability cases. Private loans are bank loans with variable or fixed rates tied to your credit, fewer flexibility options, and continued obligation in most personal-circumstance changes.
This calculator handles standard fixed-payment scenarios (10-year, 15-year, 20-year repayment), income-driven scenarios (SAVE/PAYE/REPAYE plans capping payment at percentage of income), and accelerated-payoff scenarios (extra payments toward principal). Output: monthly payment, total interest, payoff date, and key trade-offs across plan choices.
How to use this calculator
Enter loan balance, interest rate, and loan type (federal undergraduate, federal graduate, federal PLUS, private). Federal subsidized loans don't accrue interest during in-school and grace periods; unsubsidized and private do. The calculator handles these differences.
Select your repayment plan: Standard (fixed payment over 10 years), Graduated (lower early, higher later, 10 years), Extended (25 years for balances over $30K), Income-Driven (10-25 years with payment capped at 5-15% of discretionary income depending on plan). The Income-Driven plans (SAVE, PAYE, REPAYE, IBR) are the most flexible but generally produce more total interest.
Enter your annual gross income for income-driven calculations. Recently legislated SAVE plan: 5% of discretionary income for undergrad loans, 10% for graduate loans. Discretionary income = AGI − 225% of federal poverty line for household size. Payment can be $0 for low-income borrowers; balance grows or shrinks depending on interest accrual vs payment.
Indicate employment plans: public service employment qualifies for Public Service Loan Forgiveness (PSLF) — forgiveness of remaining balance after 120 qualifying monthly payments while working full-time in qualifying employment (government, 501(c)(3) nonprofits, AmeriCorps, Peace Corps, certain religious organizations). This makes income-driven repayment dramatically more attractive for public-service workers.
Understanding your results
The calculator returns monthly payment, total amount paid (principal + interest) over the payoff period, payoff date, and a comparison table showing the trade-offs between plan options for your specific balance and income.
How to read it. A $50,000 federal loan at 6.5% on standard 10-year repayment: monthly payment $568, total interest $18,144, total paid $68,144, payoff in 10 years. Same loan on SAVE (assume $65K AGI, single, undergraduate): payment $108/month for first 5 years (low income relative to balance), payment grows as income grows. If income grows to $100K average over 25 years and you don't pay off early, total paid over 25 years: roughly $90,000 — more interest, but cash flow significantly easier during early career.
The PSLF math. Same $50K loan, income-driven repayment, public-service employment. Total payments over 120 months at typical PSLF participant income trajectory: $35,000-55,000. After 120 qualifying payments, balance forgiven (no tax under current rules through 2025; potentially taxable after that). Compared to standard repayment's $68,144 total, PSLF saves $13K-33K depending on income trajectory. For public-service workers, PSLF is often the right choice mathematically even with the 10-year commitment to qualifying employment.
The refinance trade-off. Private refinancing can reduce interest rates (currently 5-7% for strong credit borrowers vs 6.5-8% federal). For $50K at 6.5% federal vs 5% private over 10 years: $568/month vs $530/month. Total interest: $18,144 vs $13,640. Savings: $4,504. But: refinancing loses federal protections (income-driven repayment, forbearance, PSLF eligibility, death/disability discharge). Refinance is appropriate when: (a) you have stable high income, (b) you don't qualify for PSLF, (c) you're paying off aggressively rather than minimizing payment. Refinance is wrong when: (a) you might need income-driven repayment, (b) you work in public service, (c) you anticipate income volatility.
The accelerate-payoff math. Same $50K loan at 6.5%, paying $700/month instead of $568. Payoff in 7.7 years instead of 10. Total interest: $13,832 vs $18,144. Saves $4,312 and 27 months of payments. The math favors acceleration unless the extra $132/month could be invested at returns above 6.5% real (which is plausible but not guaranteed).
A worked example
Aisha, 28, two years out of medical residency, owes $245,000 in federal student loans (mostly grad PLUS at 7.5% average). She just took her first attending position at $295,000/year in a private practice. She's deciding between (a) standard 10-year repayment for fast payoff, (b) income-driven for cash flow, (c) refinancing privately at 5.5%.
Standard 10-year: $2,910/month, total paid $349,200, total interest $104,200. Aggressive but doable on her income. Payoff in 10 years.
SAVE plan (income-driven): 10% of discretionary income. AGI $295K minus 225% FPL household 1 ($33,975) = discretionary $261,025. Annual payment 10% = $26,103, monthly $2,175. Slightly less than standard. Over 25 years with similar income, total paid around $400,000+ (more interest due to longer term). No PSLF eligibility since she's in private practice.
Private refinance at 5.5% / 10 years: monthly $2,659, total paid $319,100, total interest $74,100. Saves $30,000 in interest vs standard. But loses all federal protections including any future income-driven flexibility if she goes part-time during family-planning years or income drops in a recession.
Aishaaa's decision: refinance to 5.5% but use a shorter 7-year term. Monthly $3,545 — aggressive but very affordable on her $295K income. Payoff at age 35. Total interest: $52,200. She accepts the loss of federal protections because (a) her income is high and stable, (b) she has $40K emergency fund covering 6+ months of expenses, (c) she's not in public service so PSLF isn't relevant. The math wins: $52K total interest vs $104K on standard or $75K on 10-year refinance. Savings of $50K+ that she redirects to maxing her 401(k), backdoor Roth IRA, and after-tax investing.
Alternative scenario: Aisha in public service (resident in a public hospital with $80K stipend, hoping to stay public-sector long-term). Standard repayment unaffordable on $80K. SAVE plan: 10% discretionary = ~$4,600 annual / $383/month. Cumulative payments over 10 years of public service: $46K-65K depending on income growth. PSLF forgives remaining $200K+. Public service path is dramatically cheaper despite the lower lifetime income — PSLF is the single most powerful student loan benefit available to public-sector borrowers.
Related resources
For underlying loan-payment math, see Loan Amortization. For DTI implications when student loans appear in mortgage applications, the DTI Ratio Calculator. For college cost context before taking on debt, the College Net Price Calculator and Pell Grant Estimator. The federal studentaid.gov hosts authoritative information on federal loan types, repayment plans, and forgiveness programs; the official Loan Simulator models all federal plan options.